[PATCH v3 1/2] mfd: add stmpe-i2c driver

[Sascha Hauer]

On Tue, Sep 04, 2012 at 11:58:45AM +0200, Steffen Trumtrar wrote:
> The stmpe mfds can be connected via i2c and spi. This driver provides the basic
> infrastructure for the i2c kind. It can be added as a normal i2c-device in the
> board code. To enable functions a platform_data struct has to be provided, that
> describes what parts of the chip are to be used.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
> ---
> +static struct stmpe_client_info i2c_ci = {
> +	.read_reg = stmpe_reg_read,
> +	.write_reg = stmpe_reg_write,
> +};
> +
> +static int stmpe_probe(struct device_d *dev)
> +{
> +	struct stmpe_platform_data *pdata = dev->platform_data;
> +	struct stmpe *stmpe_dev;
> +
> +	if (!pdata) {
> +		dev_dbg(dev, "no platform data\n");
> +		return -ENODEV;
> +	}
> +
> +	stmpe_dev = xzalloc(sizeof(struct stmpe));
> +	stmpe_dev->cdev.name = DRIVERNAME;
> +	stmpe_dev->client = to_i2c_client(dev);
> +	stmpe_dev->cdev.size = 191;		/* 191 known registers */
> +	stmpe_dev->cdev.dev = dev;
> +	stmpe_dev->cdev.ops = &stmpe_fops;
> +	stmpe_dev->pdata = pdata;
> +	dev->priv = stmpe_dev;
> +	i2c_ci.stmpe = stmpe_dev;

This breaks for multiple instances of a stmpe device. You have to
allocate a static struct stmpe_client_info dynamically.

> +
> +	if (pdata->blocks &= STMPE_BLOCK_GPIO)
> +		add_generic_device("stmpe-gpio", 0, NULL, pdata->base, 0x10, IORESOURCE_MEM, &i2c_ci);

This issues:

drivers/mfd/stmpe-i2c.c: In function 'stmpe_probe':
drivers/mfd/stmpe-i2c.c:135:3: warning: passing argument 4 of 'add_generic_device' makes integer from pointer without a cast [enabled by default]
include/driver.h:197:18: note: expected 'resource_size_t' but argument is of type 'void *'

The base and size refer to the iomem space. As an i2c device we do not
have iomem here, so this is wrong.

Looking further at it it seems to be unused by the gpio driver anyway,
so you can just pass 0, 0 as iomem and size.


> +struct stmpe_platform_data {
> +	enum	stmpe_revision	revision;
> +	enum	stmpe_blocks	blocks;
> +	void	__iomem		*base;

This is unused, please remove.

> +	int			gpio_base;
> +};
> +
> +
> +extern int stmpe_reg_read(struct stmpe *priv, u32 reg, u8 *val);
> +extern int stmpe_reg_write(struct stmpe *priv, u32 reg, u8 val);
> +extern int stmpe_set_bits(struct stmpe *priv, u32 reg, u8 mask, u8 val);

no 'extern' for function prototypes please.

Sascha

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